Where primates have flat fingernails?

Flat nails — a gift of evolution; they distinguish the modern and fossil primates from their more ancient ancestors who were armed with sharp claws. American anthropologists found that the transition from claws to nails was smooth, and 10 million years ago some species of primates have survived several claws with which they were combing wool.

Man is, as Plato said, an animal on two feet and flat nails. Last update, according to legend, was intended to distinguish human from cock, who also walks on two legs. Flat nails were already in the early primates that lived 50 million years ago and resembled more lemurs than apes.

The ancestors of primates were common claws — rounded keratin growths on the ends of the fingers, designed to tear and scratching. In the course of evolution primates have lost this weapon, and instead got soft and sensitive fingertips, allowing you to manipulate small objects — or, as in the case of a lemur-like creatures, cleverly cling to the branches of the trees.

How did the transition from claws to nails, it is still not clear; you can only judge by the preserved bones of the fingers, and such discoveries are rare.

This week a group of American anthropologists published in the Journal of Human Evolution article with the results of the analysis of the seven found in the state of Wyoming phalanges of the early primates of five different types, including Teilhardina brandti — perhaps the earliest-known Primate species (its representatives lived 56 million years ago). Scientists came to the conclusion that, along with flat nails from early primates were long claws designed for grooming — grooming (grooming claws). Such claws (one or two fingers lower limbs) to help modern-day lemurs to care for themselves in the absence of his comrades.

The authors believe that the evolution of flat nails were more difficult than assumed; the ancestors of modern primates with flat nails “grooming claws” on some fingers were even 10 million years ago, the scientists conclude. Only when the apes have formed a sophisticated community and learned to help each other to comb the hair and catching in her living insects, it became advantageous to have flat nails and sensitive pads on all fingers.